A wizard spell on a spell scroll can be copied just as spells in spellbooks can be copied. When a spell is copied from a spell scroll, the copier must succeed on a DC 10 + Spell level -> Arcana check.

If the check succeeds, the spell is successfully copied. Whether the check succeeds or fails, the spell scroll is destroyed.

For each level of the spell, the process takes 2 hours and costs 50 gp. The cost represents material components you expend as you experiment with the spell to master it, as well as the fine inks you need to record it. Once you have spent this time and money, you can prepare the spell just like your other spells, because it is written in your spellbook.